1. Field of the Invention
The present invention relates to transcutaneous energy transmission systems wherein power and data is transmitted to implanted cardiac assist devices using an external transmitting coil and subcutaneously located receiving coil.
2. Description of the Art
The advent of implantable cardiac assist devices such as artificial hearts, ventricular assist devices, and the like, has lead to a concomitant need for a power source that meets the significant power requirements for such devices yet permits meaningful patient mobility.
One such power transmission system transcutaneously transmits power to a Left Ventricle Assist Device (LVAD), but has no provision for data communications. Given the complexity of many cardiac assist devices, there is a need to receive data from the device which may include ECG, blood pressure, and device status information, as well as transmit programming and control information to the device, as needed to maintain system operation. It is desirable to combine energy transmission and data communication into a unitary system.
Another power transmission system allows bidirectional data transmission at 300 to 1200 baud. However, this system limits the data transfer speeds by making the data link and power conversion circuitry interdependent. A data transmission rate of 1200 baud is not fast enough to allow continuous, high resolution monitoring of multiple signals such as ECGs, blood pressure, motor control waveforms, etc., used in advanced, implanted cardiac assist systems.
The present invention uses an external coupler in conjunction with subcutaneously-located coupler for both power and data transmission. The data transmission technique employed in the present invention can be capable of data transmission rates exceeding 19200 bits per second without compromising the power transmission scheme. The proposed transcutaneous energy and data transmission system provides data transmission speeds required for programming and monitoring advanced implanted cardiac assist systems.